<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>

<body>
    <script>
        function* t1(){
            yield "a"
            yield "b"
        }

        function* test() {
            yield* t1();
            yield 1;
            yield 2;
            yield 3;
        }

        const generator = test();
    </script>
</body>

</html>